Strict environmental rules and inspections to ensure standards are being met has meant cutbacks and shutdowns in high-polluting industries such as mining, smelting and recycling, hitting China’s output of metal.

China is the world’s largest producer and consumer of refined industrial and minor metals.

China’s environment ministry recently said it was drawing up details of a new “battle plan” to curb pollution over the 2018-2020 period, after the previous five-year plan helped reduce hazardous pollution.

“China’s increasingly stringent environmental policy was a big story in 2017 and will remain a key driver for the metals market in 2018,” Ming He, senior manager at consultants Wood Mackenzie said.

“Environmental policies should continue to cause more supply disruptions. Environmental campaigns and safety checks will lead to more mine supply curtailments or closures.”

Analysts say last year’s strong price gains of minor metals produced in China are likely to be repeated this year.

One top performer is vanadium, used to strengthen steel and a vital element in batteries for grid storage.

Prices of ferro-vanadium VAN-FERRO-LON have more than doubled from January 2017 to $59 a kg to nine-year highs.